Macbook Pro M1 microphone input channels

I recently traded in my 2017 MacBook Pro for a 2021 M1 Pro MacBook. Both computers ran macOS Monterey. I decided that I wanted a clean install of the OS and all my apps so I set aside a good chunk of time reinstalled everything. When I was configuring Audacity I noticed that I only had the option of 1 input channel (my old MBPro had either 1 or 2 input channels as options). I opened up Audio MIDI setup and, sure enough, the built-in microphone only has 1 channel as the only option.

This is the first time I've seen this for any MBPro built-in mic. Is this an M1 thing? A Monterey thing? or does my computer have an issue?